This invention relates to a crop harvesting machine which has a windrow grouper to which harvested crop is delivered and which rotates about an upwardly extending axis. The machine can be a mower conditioner for a grass crop. A windrow grouper is a component which combines into one, at least two windrows each of which is made on a single pass of the harvesting machine.
Conventionally, grass to be harvested is cut by a mower and delivered rearwardly to form a windrow on the ground, where it is left for a period to dry. A further machine then is used to pick the crop up from the windrow.
Some years ago, it was proposed in Swiss patent specification No. 480,776 to form a double windrow on every second pass of a mower across a field by providing the mower at its rearward part with a windrow grouper which functions on the second pass only and which rakes the crop across the ground from the second windrow just formed into the previous windrow. Subsequently, the crop lying in the double windrow thus produced is picked up in half the number of the passes which would have been needed had the crop been distributed in single rather than double windrows. The rake disclosed in the Swiss patent specification is rotatable about a horizontal or vertical axis.
One difficulty with such an arrangement is that foreign bodies and other rubbish such as stones would tend to be raked with the crop from the second windrow into the double windrow. These foreign bodies clearly present a mechanical danger to machinery used to pick up the double windrow and also a health hazard to cattle which may be fed on the harvested crop.